/*

 * rdswitch.c

 *

 * Copyright (C) 1991-1995, Thomas G. Lane.

 * This file is part of the Independent JPEG Group's software.

 * For conditions of distribution and use, see the accompanying README file.

 *

 * This file contains routines to process some of cjpeg's more complicated

 * command-line switches.  Switches processed here are:

 *	-qtables file		Read quantization tables from text file

 *	-scans file		Read scan script from text file

 *	-qslots N[,N,...]	Set component quantization table selectors

 *	-sample HxV[,HxV,...]	Set component sampling factors

 */



#include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */

#include <ctype.h>		/* to declare isdigit(), isspace() */





/* Hack: get access to jpeg_zigzag_order[] table in jutils.c.

 * Since it's declared in jpegint.h, normally can't see it from an application.

 */

#ifdef NEED_SHORT_EXTERNAL_NAMES

#define jpeg_zigzag_order	jZIGTable

#endif

extern const int jpeg_zigzag_order[];





LOCAL int

text_getc (FILE * file)

/* Read next char, skipping over any comments (# to end of line) */

/* A comment/newline sequence is returned as a newline */

{

  register int ch;

  

  ch = getc(file);

  if (ch == '#') {

    do {

      ch = getc(file);

    } while (ch != '\n' && ch != EOF);

  }

  return ch;

}





LOCAL boolean

read_text_integer (FILE * file, long * result, int * termchar)

/* Read an unsigned decimal integer from a file, store it in result */

/* Reads one trailing character after the integer; returns it in termchar */

{

  register int ch;

  register long val;

  

  /* Skip any leading whitespace, detect EOF */

  do {

    ch = text_getc(file);

    if (ch == EOF) {

      *termchar = ch;

      return FALSE;

    }

  } while (isspace(ch));

  

  if (! isdigit(ch)) {

    *termchar = ch;

    return FALSE;

  }



  val = ch - '0';

  while ((ch = text_getc(file)) != EOF) {

    if (! isdigit(ch))

      break;

    val *= 10;

    val += ch - '0';

  }

  *result = val;

  *termchar = ch;

  return TRUE;

}





GLOBAL boolean

read_quant_tables (j_compress_ptr cinfo, char * filename,

		   int scale_factor, boolean force_baseline)

/* Read a set of quantization tables from the specified file.

 * The file is plain ASCII text: decimal numbers with whitespace between.

 * Comments preceded by '#' may be included in the file.

 * There may be one to NUM_QUANT_TBLS tables in the file, each of 64 values.

 * The tables are implicitly numbered 0,1,etc.

 * NOTE: does not affect the qslots mapping, which will default to selecting

 * table 0 for luminance (or primary) components, 1 for chrominance components.

 * You must use -qslots if you want a different component->table mapping.

 */

{

  FILE * fp;

  int tblno, i, termchar;

  long val;

  unsigned int table[DCTSIZE2];



  if ((fp = fopen(filename, "r")) == NULL) {

    fprintf(stderr, "Can't open table file %s\n", filename);

    return FALSE;

  }

  tblno = 0;



  while (read_text_integer(fp, &val, &termchar)) { /* read 1st element of table */

    if (tblno >= NUM_QUANT_TBLS) {

      fprintf(stderr, "Too many tables in file %s\n", filename);

      fclose(fp);

      return FALSE;

    }

    table[0] = (unsigned int) val;

    for (i = 1; i < DCTSIZE2; i++) {

      if (! read_text_integer(fp, &val, &termchar)) {

	fprintf(stderr, "Invalid table data in file %s\n", filename);

	fclose(fp);

	return FALSE;

      }

      /* Convert from natural order in the file to zigzag table order. */

      table[jpeg_zigzag_order[i]] = (unsigned int) val;

    }

    jpeg_add_quant_table(cinfo, tblno, table, scale_factor, force_baseline);

    tblno++;

  }



  if (termchar != EOF) {

    fprintf(stderr, "Non-numeric data in file %s\n", filename);

    fclose(fp);

    return FALSE;

  }



  fclose(fp);

  return TRUE;

}





#ifdef C_MULTISCAN_FILES_SUPPORTED



LOCAL boolean

read_scan_integer (FILE * file, long * result, int * termchar)

/* Variant of read_text_integer that always looks for a non-space termchar;

 * this simplifies parsing of punctuation in scan scripts.

 */

{

  register int ch;



  if (! read_text_integer(file, result, termchar))

    return FALSE;

  ch = *termchar;

  while (ch != EOF && isspace(ch))

    ch = text_getc(file);

  if (isdigit(ch)) {		/* oops, put it back */

    if (ungetc(ch, file) == EOF)

      return FALSE;

    ch = ' ';

  } else {

    /* Any separators other than ';' and ':' are ignored;

     * this allows user to insert commas, etc, if desired.

     */

    if (ch != EOF && ch != ';' && ch != ':')

      ch = ' ';

  }

  *termchar = ch;

  return TRUE;

}





GLOBAL boolean

read_scan_script (j_compress_ptr cinfo, char * filename)

/* Read a scan script from the specified text file.

 * Each entry in the file defines one scan to be emitted.

 * Entries are separated by semicolons ';'.

 * An entry contains one to four component indexes,

 * optionally followed by a colon ':' and four progressive-JPEG parameters.

 * The component indexes denote which component(s) are to be transmitted

 * in the current scan.  The first component has index 0.

 * Sequential JPEG is used if the progressive-JPEG parameters are omitted.

 * The file is free format text: any whitespace may appear between numbers

 * and the ':' and ';' punctuation marks.  Also, other punctuation (such

 * as commas or dashes) can be placed between numbers if desired.

 * Comments preceded by '#' may be included in the file.

 * Note: we do very little validity checking here;

 * jcmaster.c will validate the script parameters.

 */

{

  FILE * fp;

  int scanno, ncomps, termchar;

  long val;

  jpeg_scan_info * scanptr;

#define MAX_SCANS  100		/* quite arbitrary limit */

  jpeg_scan_info scans[MAX_SCANS];



  if ((fp = fopen(filename, "r")) == NULL) {

    fprintf(stderr, "Can't open scan definition file %s\n", filename);

    return FALSE;

  }

  scanptr = scans;

  scanno = 0;



  while (read_scan_integer(fp, &val, &termchar)) {

    if (scanno >= MAX_SCANS) {

      fprintf(stderr, "Too many scans defined in file %s\n", filename);

      fclose(fp);

      return FALSE;

    }

    scanptr->component_index[0] = (int) val;

    ncomps = 1;

    while (termchar == ' ') {

      if (ncomps >= MAX_COMPS_IN_SCAN) {

	fprintf(stderr, "Too many components in one scan in file %s\n",

		filename);

	fclose(fp);

	return FALSE;

      }

      if (! read_scan_integer(fp, &val, &termchar))

	goto bogus;

      scanptr->component_index[ncomps] = (int) val;

      ncomps++;

    }

    scanptr->comps_in_scan = ncomps;

    if (termchar == ':') {

      if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')

	goto bogus;

      scanptr->Ss = (int) val;

      if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')

	goto bogus;

      scanptr->Se = (int) val;

      if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')

	goto bogus;

      scanptr->Ah = (int) val;

      if (! read_scan_integer(fp, &val, &termchar))

	goto bogus;

      scanptr->Al = (int) val;

    } else {

      /* set non-progressive parameters */

      scanptr->Ss = 0;

      scanptr->Se = DCTSIZE2-1;

      scanptr->Ah = 0;

      scanptr->Al = 0;

    }

    if (termchar != ';' && termchar != EOF) {

bogus:

      fprintf(stderr, "Invalid scan entry format in file %s\n", filename);

      fclose(fp);

      return FALSE;

    }

    scanptr++, scanno++;

  }



  if (termchar != EOF) {

    fprintf(stderr, "Non-numeric data in file %s\n", filename);

    fclose(fp);

    return FALSE;

  }



  if (scanno > 0) {

    /* Stash completed scan list in cinfo structure.

     * NOTE: for cjpeg's use, JPOOL_IMAGE is the right lifetime for this data,

     * but if you want to compress multiple images you'd want JPOOL_PERMANENT.

     */

    scanptr = (jpeg_scan_info *)

      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

				  scanno * SIZEOF(jpeg_scan_info));

    MEMCOPY(scanptr, scans, scanno * SIZEOF(jpeg_scan_info));

    cinfo->scan_info = scanptr;

    cinfo->num_scans = scanno;

  }



  fclose(fp);

  return TRUE;

}



#endif /* C_MULTISCAN_FILES_SUPPORTED */





GLOBAL boolean

set_quant_slots (j_compress_ptr cinfo, char *arg)

/* Process a quantization-table-selectors parameter string, of the form

 *     N[,N,...]

 * If there are more components than parameters, the last value is replicated.

 */

{

  int val = 0;			/* default table # */

  int ci;

  char ch;



  for (ci = 0; ci < MAX_COMPONENTS; ci++) {

    if (*arg) {

      ch = ',';			/* if not set by sscanf, will be ',' */

      if (sscanf(arg, "%d%c", &val, &ch) < 1)

	return FALSE;

      if (ch != ',')		/* syntax check */

	return FALSE;

      if (val < 0 || val >= NUM_QUANT_TBLS) {

	fprintf(stderr, "JPEG quantization tables are numbered 0..%d\n",

		NUM_QUANT_TBLS-1);

	return FALSE;

      }

      cinfo->comp_info[ci].quant_tbl_no = val;

      while (*arg && *arg++ != ',') /* advance to next segment of arg string */

	;

    } else {

      /* reached end of parameter, set remaining components to last table */

      cinfo->comp_info[ci].quant_tbl_no = val;

    }

  }

  return TRUE;

}





GLOBAL boolean

set_sample_factors (j_compress_ptr cinfo, char *arg)

/* Process a sample-factors parameter string, of the form

 *     HxV[,HxV,...]

 * If there are more components than parameters, "1x1" is assumed for the rest.

 */

{

  int ci, val1, val2;

  char ch1, ch2;



  for (ci = 0; ci < MAX_COMPONENTS; ci++) {

    if (*arg) {

      ch2 = ',';		/* if not set by sscanf, will be ',' */

      if (sscanf(arg, "%d%c%d%c", &val1, &ch1, &val2, &ch2) < 3)

	return FALSE;

      if ((ch1 != 'x' && ch1 != 'X') || ch2 != ',') /* syntax check */

	return FALSE;

      if (val1 <= 0 || val1 > 4 || val2 <= 0 || val2 > 4) {

	fprintf(stderr, "JPEG sampling factors must be 1..4\n");

	return FALSE;

      }

      cinfo->comp_info[ci].h_samp_factor = val1;

      cinfo->comp_info[ci].v_samp_factor = val2;

      while (*arg && *arg++ != ',') /* advance to next segment of arg string */

	;

    } else {

      /* reached end of parameter, set remaining components to 1x1 sampling */

      cinfo->comp_info[ci].h_samp_factor = 1;

      cinfo->comp_info[ci].v_samp_factor = 1;

    }

  }

  return TRUE;

}

